This invention relates to a device for selective electrochemical polishing, more specifically, to an apparatus for removing the surface layer of material at localized areas of alloy test specimens. The Government has rights in this invention pursuant to Contract No. DE-AC12-76-SN00052 awarded by the U.S. Department of Energy.
Heretofore, various electrochemical polishing techniques have been known and utilized for the purpose of surface treatment of various alloy materials by the use of anodic dissolution which utilized bulk circulating electrolytes and large surface electrodes remote from the desired surface to be removed. These techniques would cause metal removal from all of the exterior test specimen surfaces but would not be advantageous in facilitating controlled and uniform surface removal from localized areas. U.S. Pat. Nos. 3,793,169 and 3,816,272 address local selective removal of metal by electropolishing. However, the methodology is not considered applicable to specialized materials such as threaded fasteners or uniaxial notched test specimens. Furthermore, these disclosures do not identify or recognize the need to assure and produce metal surfaces which are free from metal grain boundary attack.